Two Fundamentally Different Cell Architectures: Two Types of Cells Two Fundamentally Different Cell Architectures: 2) A eukaryotic cell 1) A prokaryotic cell

Prokaryotic cells have no nucleus or organelles enclosed within membranes. All species in the domains Archaea and Eubacteria have prokaryotic cells.

Eukaryotic cells have a nucleus and organelles that are surrounded by membranes. Each organelle does a specific cell function. All species in the Eukaryota domain (protists, fungi, plants, and animals) have eukaryotic cells. Individual protists have only one cell, while plants and animals can have trillions of cells.

Prokaryotes vs. Eukaryotes

Size comparison??

PROKARYOTES vs. EUKARYOTES: Differences (Location)

Similarities: Common Features of ALL CELLS!

An idealized animal cell.

A rat liver cell (with color enhancement to show organelles).

What Do Those Parts Do?

Shapes of Prokaryotes Cocci = spherical (round) Bacillus = (rod shaped) Spirilla = helical (spiral)

Functions of Eukaryotic Cell Features Structure Function(s) Plasma Membrane 1. Regulates passage of materials into and out of cell 2. Cell-Cell Recognition

Functions of Eukaryotic Cell Features Structure Function(s) Cell Wall (protists, fungi, plants) Controls cell shape, protects, supports

Functions of Eukaryotic Cell Features Structure Function(s) Nucleus Carrier of genetic material DNA + protein = chromatin 2. Governs cell activities 3. Directs cell reproduction Surrounded by Membrane = nuclear envelope Contains nucleolus—produces ribosomes which synthesize proteins

Functions of Eukaryotic Cell Features SER RER Functions of Eukaryotic Cell Features Structure Function(s) Rough Endoplasmic Reticulum (RER) Associated ribosomes produce proteins Prepares proteins for export Smooth Endoplasmic Reticulum (SER) Lipid Synthesis Drug detoxification Transport of proteins from RER

Functions of Eukaryotic Cell Features Structure Function(s) Golgi Apparatus Collects, modifies, packages and distributes proteins and lipids from ER

Functions of Eukaryotic Cell Features Structure Function(s) Lysosome Contains digestive enzymes to digest food in protists or destroy aging organelles

Endomembrane System Rough Endoplasmic Reticulum Smooth Endoplasmic Reticulum Vesicle Golgi Apparatus Lysosome Vesicle Vesicle Plasma Membrane

Functions of Eukaryotic Cell Features Structure Function Peroxisome Removes harmful oxidants from cells

Functions of Eukaryotic Cell Features Structure Function Mitochondrion Captures energy from organic molecules, producing ATP

Functions of Eukaryotic Cell Features Structure Function Chloroplast (protists, plants) Photosynthesis: Uses light energy to produce organic molecules

Functions of Eukaryotic Cell Features Structure Function(s) Cytoskeleton Maintains cell shape Anchors organelles and proteins Allows for organelle movement and cellular movement in some cell types

Functions of Eukaryotic Cell Features Structure Function Centriole Gives rise to basal bodies that produce cilia or flagella

Functions of Eukaryotic Cell Features Structure Function(s) Vacuole Central vacuole (plants) stores waste, maintains turgidity. Contractile vacuole (protists) maintains water balance. Food vacuole (protists) fuses with lysosome for digestion.

Functions of Eukaryotic Cell Features Structure Function(s) Cilia and Flagella Move substances across cell surface in lungs, fallopian tubes Cell movement in sperm, protists

Asexual vs. Sexual Reproduction

Asexual reproduction A form of reproduction which does not involve meiosis or fertilization. Asexual reproduction = one parent. The primary form of reproduction for single-celled organisms such as archaea, bacteria, and protists. Many plants and fungi reproduce mostly asexually as well.

Sexual Reproduction Results in increasing genetic diversity of the offspring. Characterized by two processes: meiosis, halving of the number of chromosomes fertilization, combination of two gametes and the restoration of the original number of chromosomes During meiosis, chromosomes usually cross over = genetic recombination. Primary method of reproduction for the vast majority of visible organisms, including almost all animals and plants.

Binary Fission Asexual Cell splits and replicated DNA goes with each part Prokaryotes, Bacteria + Fast and easy - Everybody has the same DNA

Bacterial Conjugation Asexual, A bacteria shoots out a tube and sends a piece of its DNA to another bacteria Bacteria + Mixes DNA - “Parent” loses a little piece of DNA

Fragmentation/ regeneration Asexual Body of parent breaks and produces offspring Fungi, moss, sea stars, planarian + Easy - Parent broken, same DNA Fragmentation or Clonal Fragmentation is a form of asexual reproduction or cloning where an organism is split into fragments. The splitting may or may not be intentional. Each of these fragments develop into mature, fully grown individuals that are a clone of the original organism. If the organism is split any further the process is repeated. Fragmentation is seen in many organisms such as molds, some annelid worms, and starfish. Binary fission of single-celled organisms such bacteria, protozoa and many algae is a type of fragmentation. Molds, yeast, and mushrooms, all of which are part of the Fungi kingdom, produce tiny filaments called hyphae. These hyphae obtain food and nutrients from the body of other organisms to grow and fertilize. Then a piece of hyphae breaks off and grows into a new individual and the cycle continues. Fragmentation is observed in nonvascular plants as well, liverworts and mosses.

Fragmentation/ regeneration Fragmentation or Clonal Fragmentation is a form of asexual reproduction or cloning where an organism is split into fragments. The splitting may or may not be intentional. Each of these fragments develop into mature, fully grown individuals that are a clone of the original organism. If the organism is split any further the process is repeated. Fragmentation is seen in many organisms such as molds, some annelid worms, and starfish. Binary fission of single-celled organisms such bacteria, protozoa and many algae is a type of fragmentation. Molds, yeast, and mushrooms, all of which are part of the Fungi kingdom, produce tiny filaments called hyphae. These hyphae obtain food and nutrients from the body of other organisms to grow and fertilize. Then a piece of hyphae breaks off and grows into a new individual and the cycle continues. Fragmentation is observed in nonvascular plants as well, liverworts and mosses. Moss

Budding Asexual Offspring grows out of parent Yeast, hydras + Fast, somewhat easy - Same DNA

Pollination Sexual Pollen is delivered to female part of plant Flowering plants + Plants don’t have to move, mixes DNA - Need external source for pollination to take place; wind, bee, bat, butterfly etc.

Pollination

Sexual Reproduction Sexual DNA from 2 individuals, egg and sperm cell fertilize. Animals, Plants + Diverse DNA - Takes a long time, 2 individuals needed

Sexual Reproduction

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